KARACHI: Gushing rainwater entered a number of low-lying localities and villages located on the outskirts of the city as well as flooding a section of Karachi-Hyderabad Motorway, also called M9, causing its closure for around five hours on Tuesday.

While no government official was available for confirmation, there were reports that the flooding of M9 was caused by a breach in the Thaddo dam located in Gadap Town, as had happened in the past.

“We had to close one-and-a-half-kilometre section of the M9 after it got submerged around 11am. The traffic was diverted on the other track,” said a spokesperson for the Motorway Police.

Karachi receives 164.9mm, or 6.4 inches, of rain in two days

According to him, the situation improved gradually when rain stopped after a few hours, reducing water pressure.

“The water found its way and slowly discharged into culverts,” he said, adding that the portion was opened by 4pm.

To a question, he said he could not confirm but apparently the flooding was caused by a breach in a nearby dam.

A visit to the spot showed that apparently culverts were too small for a sudden rush of water, which led to the closure of the track.

The specific road track, where flooding occurred, is located opposite a housing society, Saadi Town, which has experienced similar flooding quite a few times in the past.

One could see rainwater gushing out of the culverts into the housing society built on a low-lying area.

It also entered other low-lying societies and villages adjacent to the Northern Bypass as well as houses located along the Lyari River, which had swollen due to incessant rain for the past two days.

It is important to mention that flooding within the city and parts of its suburbs has become a regular feature whenever Karachi experiences heavy downpour.

Experts blame this situation mainly on the failure of the government to protect and preserve the city’s natural drainage routes that had either been completely closed or blocked by unplanned development.

In addition, the city has not been able to develop a proper solid waste management system including periodic cleaning of existing drains within Karachi.

Speaking to Dawn, seasoned architect and urban planner Dr Noman Ahmed said: “Areas located in the north and north-east of the city’s suburbs have a peculiar topography and that is the marked difference in the land’s level.”

For decades, some of these areas were reserved for livestock raising, while others located near a water body for agriculture, he said. This nature of topography was well protected till 1970s and culverts were built if the road/highway was built on a rain-catchment area.

“But, this [strategy] was changed later when projects like Scheme 33, Saadi Town, etc, came in violation to this topography. Under Scheme 33, only land was allocated and no provision was made for natural drains,” he said.

The massive extraction of sand along rivers and drains, he pointed out, also greatly damaged the city’s natural barriers, equally affected by newly built housing societies such as Bahria Town and DHA City.

On the design of M9, he said: “The current situation should serve as an eye-opener. The track should have been designed in a way that it could withstand all forms of weather. We should have learnt from the 2012 Saadi Town flooding that confined hundreds of people in their homes.”

Asked about the breach in any dam that might have contributed to the track’s flooding, he said it might be possible as there were several locally built reservoirs on the outskirts of the city, which might have overflowed and flooded low-lying areas.

Drizzle forecast

The Met department forecast cloudy weather with light rain/drizzle on Wednesday.

During the two-day rain spell, the Met office recorded maximum 164.9 millimetres, or 6.4 inches, of rain in Surjani Town followed by 149mm, or 5.8 inches, of rain in Saddar.

The met office recorded 78mm of rain in Gulshan-i-Hadeed, 88mm in North Karachi, 65mm in Nazimabad, 59 in Landhi, 62.3 in the old area (Airport), 79.4mm in Gulistan-i-Jauhar, 87mm in Faisal Base and 82mm in Masroor Base.

Published in Dawn, July 31st, 2019